Add new "\import" pragma

core/modules/parsers/wikiparser/rules/import.js

@@ -0,0 +1,53 @@
+/*\
+title: $:/core/modules/parsers/wikiparser/rules/import.js
+type: application/javascript
+module-type: wikirule
+
+Wiki pragma rule for importing variable definitions
+
+```
+\import [[$:/core/ui/PageMacros]] [all[shadows+tiddlers]tag[$:/tags/Macro]!has[draft.of]]
+```
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+exports.name = "import";
+exports.types = {pragma: true};
+
+/*
+Instantiate parse rule
+*/
+exports.init = function(parser) {
+	this.parser = parser;
+	// Regexp to match
+	this.matchRegExp = /^\\import[^\S\n]/mg;
+};
+
+/*
+Parse the most recent match
+*/
+exports.parse = function() {
+	var self = this;
+	// Move past the pragma invocation
+	this.parser.pos = this.matchRegExp.lastIndex;
+	// Parse the filter terminated by a line break
+	var reMatch = /(.*)(\r?\n)|$/mg;
+	reMatch.lastIndex = this.parser.pos;
+	var match = reMatch.exec(this.parser.source);
+	this.parser.pos = reMatch.lastIndex;
+	// Parse tree nodes to return
+	return [{
+		type: "importvariables",
+		attributes: {
+			filter: {type: "string", value: match[1]}
+		},
+		children: []
+	}];
+};
+
+})();